Institute of Experimental Physics , Slovak Academy of Sciences , Watsonova 47 , 040 01 Košice , Slovakia.
J Phys Chem B. 2019 Feb 14;123(6):1365-1374. doi: 10.1021/acs.jpcb.8b10638. Epub 2019 Feb 4.
We report on a mesoscale solubility reflecting the fact that solubility is achieved not only by the well-known "like likes like" or "like dissolves like" based on molecular solvation but also on mesoscale solubilization of dislike compounds characterized in that the solubility (homogeneous distribution over the whole volume of the system) is achieved on a mesoscale level ranging from tens to hundreds of nanometers. It is shown that mesoscale solubility is a spontaneously occurring, literally everywhere present phenomenon, which was hidden and overlooked for a long time. This paper reveals the physical mechanism of mesoscale solubilization comprising nucleation and aggregation accompanied by the development of significant surface zeta potentials on nanoprecipitates, giving them a long-term stability. We show that mesoscale solubilization is common for aqueous as well as nonaqueous systems. Experiments with organic solvents not capable of self-ionization (self-dissociation) instead of water also shed light on the mechanism of the generation of surface zeta potentials at hydrophobic interfaces. We identified the key parameters enabling the mesoscale solubilization and mapped its occurrence as their function. Mesoscale structures including their formation kinetics, long-term stability, and different types of solubilization procedures were characterized by scattering and ultramicroscopic visualization comprising sizing and counting.
我们报告了一种介观溶解度，它反映了这样一个事实，即溶解度不仅是基于分子溶剂化的众所周知的“相似相溶”或“相似溶解”，而且还可以在介观水平上实现不相似化合物的溶解，其特征在于溶解度（在系统的整个体积中均匀分布）是在几十到几百纳米的介观水平上实现的。结果表明，介观溶解度是一种自发发生的、无处不在的现象，它长期以来一直被隐藏和忽视。本文揭示了介观增溶的物理机制，包括成核和聚集，伴随着纳米沉淀物表面zeta 电位的显著发展，赋予它们长期稳定性。我们表明，介观增溶对于水相和非水相系统都是常见的。用不能自电离（自解离）的有机溶剂代替水进行实验，也揭示了在疏水性界面产生表面 zeta 电位的机制。我们确定了实现介观增溶的关键参数，并将其作为函数映射其发生情况。介观结构包括它们的形成动力学、长期稳定性和不同类型的增溶程序，通过散射和超微可视化进行了表征，包括粒度和计数。
